| Message ID | 1653104135-36259-1-git-send-email-lyz_cs@pku.edu.cn (mailing list archive) |
|---|---|
| State | Changes Requested |
| Headers | show |
| Series | [v3] iio: vadc: Fix potential dereference of NULL pointer | expand |
On Fri, 20 May 2022 20:35:35 -0700 Yongzhi Liu <lyz_cs@pku.edu.cn> wrote: > The return value of vadc_get_channel() needs to be checked to > avoid use of NULL pointer. Fix this by adding the null pointer > check on prop and dropping general error prints. > > Fixes: 0917de94c02f ("iio: vadc: Qualcomm SPMI PMIC voltage ADC driver") > Signed-off-by: Yongzhi Liu <lyz_cs@pku.edu.cn> Hi, Heading in the right direction. A few comments inline. Thanks, Jonathan > --- > drivers/iio/adc/qcom-spmi-vadc.c | 38 ++++++++++++++++++++++++++++---------- > 1 file changed, 28 insertions(+), 10 deletions(-) > > diff --git a/drivers/iio/adc/qcom-spmi-vadc.c b/drivers/iio/adc/qcom-spmi-vadc.c > index 34202ba..43a52b1 100644 > --- a/drivers/iio/adc/qcom-spmi-vadc.c > +++ b/drivers/iio/adc/qcom-spmi-vadc.c > @@ -358,22 +358,33 @@ static int vadc_measure_ref_points(struct vadc_priv *vadc) > vadc->graph[VADC_CALIB_ABSOLUTE].dx = VADC_ABSOLUTE_RANGE_UV; > > prop = vadc_get_channel(vadc, VADC_REF_1250MV); > + if (!prop) { > + dev_err(vadc->dev, "Please define 1.25V channel\n"); > + ret = -ENODEV; > + return ret; return -ENODEV; Same for the other case below. > + } > ret = vadc_do_conversion(vadc, prop, &read_1); > if (ret) > - goto err; Good to add a note to the patch description that vadc_do_conversion() already provides error prints in at least some of it's error paths. Thus it is reasonable to drop the extra reporting in this function. > + return ret; > > /* Try with buffered 625mV channel first */ > prop = vadc_get_channel(vadc, VADC_SPARE1); > - if (!prop) > + if (!prop) { > prop = vadc_get_channel(vadc, VADC_REF_625MV); > + if (!prop) { > + dev_err(vadc->dev, "Please define 0.625V channel\n"); > + ret = -ENODEV; > + return ret; > + } > + } > > ret = vadc_do_conversion(vadc, prop, &read_2); > if (ret) > - goto err; > + return ret; > > if (read_1 == read_2) { > ret = -EINVAL; > - goto err; > + return ret; > } > > vadc->graph[VADC_CALIB_ABSOLUTE].dy = read_1 - read_2; > @@ -381,25 +392,32 @@ static int vadc_measure_ref_points(struct vadc_priv *vadc) > > /* Ratiometric calibration */ > prop = vadc_get_channel(vadc, VADC_VDD_VADC); > + if (!prop) { > + dev_err(vadc->dev, "Please define VDD channel\n"); > + ret = -ENODEV; > + return ret; > + } > ret = vadc_do_conversion(vadc, prop, &read_1); > if (ret) > - goto err; > + return ret; > > prop = vadc_get_channel(vadc, VADC_GND_REF); > + if (!prop) { > + dev_err(vadc->dev, "Please define GND channel\n"); > + ret = -ENODEV; > + return ret; > + } > ret = vadc_do_conversion(vadc, prop, &read_2); > if (ret) > - goto err; > + return ret; > > if (read_1 == read_2) { > ret = -EINVAL; > - goto err; > + return ret; > } > > vadc->graph[VADC_CALIB_RATIOMETRIC].dy = read_1 - read_2; > vadc->graph[VADC_CALIB_RATIOMETRIC].gnd = read_2; > -err: > - if (ret) > - dev_err(vadc->dev, "measure reference points failed\n"); > > return ret; > }
diff --git a/drivers/iio/adc/qcom-spmi-vadc.c b/drivers/iio/adc/qcom-spmi-vadc.c index 34202ba..43a52b1 100644 --- a/drivers/iio/adc/qcom-spmi-vadc.c +++ b/drivers/iio/adc/qcom-spmi-vadc.c @@ -358,22 +358,33 @@ static int vadc_measure_ref_points(struct vadc_priv *vadc) vadc->graph[VADC_CALIB_ABSOLUTE].dx = VADC_ABSOLUTE_RANGE_UV; prop = vadc_get_channel(vadc, VADC_REF_1250MV); + if (!prop) { + dev_err(vadc->dev, "Please define 1.25V channel\n"); + ret = -ENODEV; + return ret; + } ret = vadc_do_conversion(vadc, prop, &read_1); if (ret) - goto err; + return ret; /* Try with buffered 625mV channel first */ prop = vadc_get_channel(vadc, VADC_SPARE1); - if (!prop) + if (!prop) { prop = vadc_get_channel(vadc, VADC_REF_625MV); + if (!prop) { + dev_err(vadc->dev, "Please define 0.625V channel\n"); + ret = -ENODEV; + return ret; + } + } ret = vadc_do_conversion(vadc, prop, &read_2); if (ret) - goto err; + return ret; if (read_1 == read_2) { ret = -EINVAL; - goto err; + return ret; } vadc->graph[VADC_CALIB_ABSOLUTE].dy = read_1 - read_2; @@ -381,25 +392,32 @@ static int vadc_measure_ref_points(struct vadc_priv *vadc) /* Ratiometric calibration */ prop = vadc_get_channel(vadc, VADC_VDD_VADC); + if (!prop) { + dev_err(vadc->dev, "Please define VDD channel\n"); + ret = -ENODEV; + return ret; + } ret = vadc_do_conversion(vadc, prop, &read_1); if (ret) - goto err; + return ret; prop = vadc_get_channel(vadc, VADC_GND_REF); + if (!prop) { + dev_err(vadc->dev, "Please define GND channel\n"); + ret = -ENODEV; + return ret; + } ret = vadc_do_conversion(vadc, prop, &read_2); if (ret) - goto err; + return ret; if (read_1 == read_2) { ret = -EINVAL; - goto err; + return ret; } vadc->graph[VADC_CALIB_RATIOMETRIC].dy = read_1 - read_2; vadc->graph[VADC_CALIB_RATIOMETRIC].gnd = read_2; -err: - if (ret) - dev_err(vadc->dev, "measure reference points failed\n"); return ret; }
The return value of vadc_get_channel() needs to be checked to avoid use of NULL pointer. Fix this by adding the null pointer check on prop and dropping general error prints. Fixes: 0917de94c02f ("iio: vadc: Qualcomm SPMI PMIC voltage ADC driver") Signed-off-by: Yongzhi Liu <lyz_cs@pku.edu.cn> --- drivers/iio/adc/qcom-spmi-vadc.c | 38 ++++++++++++++++++++++++++++---------- 1 file changed, 28 insertions(+), 10 deletions(-)